Traditional power switches are fabricated from P and N type regions of semiconductor material with metalised layers and sometimes with thin oxide layers for field-effect devices. Well known in the art are technologies such as Bipolar Junction Transistors (BJT), Junction Field Effect Transistors (JFET), Metal Oxide Field Effect Transistors (MOSFET) and Insulated Gate Biploar Transistor (IGBT) which generally switch DC voltages. Whereas Triacs, Silicon Controlled Rectifiers (SCR) as well as modified (typically back-to-back) versions of the DC switch types have been used to switch AC power. Whether fabricated on Silicon or a compound semiconductor such has Silicon Carbide (SiC) all these standard devices has one or more limitation when it comes to the common task of switching AC power on and off.
These limitations lead to the following problems.
Lack of AC switching ability.
Expensive semiconductor materials.
Complex semiconductor processing steps.
Inherent voltage drop on turn on (typ. 0.8 to 2.5 volts) limiting efficiency.
Lack of turn-off ability—can prevent implementation of short-circuit protection feature.
Complex, high-voltage, high current +ve and −ve base/gate drive circuitry.
High on-resistance for high voltage devices.
It is an object of the present invention to address the problems described above.